/*
 * @(#)NotificationQueue.java	1.0 Mar 8, 2008
 *
 *	The MIT License
 *
 *	Copyright (c) 2008 Malachi de AElfweald <malachid@gmail.com>
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:
 *
 *	The above copyright notice and this permission notice shall be included in
 *	all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *	THE SOFTWARE.
 */
package org.eoti.util.queue;

import org.eoti.util.TimeUtil;

import java.util.concurrent.ConcurrentLinkedQueue;

public abstract class NotificationQueue<E>
		extends Thread
{
	public enum State
	{
		Start,Stop,Pause;
	}

	public enum Mode
	{
		Single,Burst,All
	}

	protected TimeUtil.Unit unitOfTime;
	protected long intervalOfTime;
	protected Mode mode;
	protected State state;
	protected ConcurrentLinkedQueue<E> queue;

	public NotificationQueue(TimeUtil.Unit unitOfTime, long intervalOfTime, Mode mode)
	{
		super("NotificationQueue");
        this.unitOfTime = unitOfTime;
		this.intervalOfTime = intervalOfTime;
		this.mode = mode;
		this.state = State.Pause;
		queue = new ConcurrentLinkedQueue<E>();
	}

	public void setMode(Mode mode){this.mode = mode;}
	public Mode getMode(){return mode;}
	public void setQueueState(State state){this.state = state;}
	public State getQueueState(){return state;}

	public void queue(E element){queue.add(element);}

	public void flush()
	{
		Mode old = mode;
		setMode(Mode.All);
		send();
		setMode(old);
	}

	public void finalize()
	{
		setQueueState(State.Stop);
		queue.clear();
	}

	protected void send()
	{
		if(queue.isEmpty()) return;

		if(mode == Mode.Single) sendOne();
		else sendAll();
	}

	protected void sendOne()
	{
		send(queue.poll());
	}

	protected void sendAll()
	{
		for(E element : queue)
			send(element);
	}

	public void run()
	{
		while(state != State.Stop)
		{
			if(state != State.Pause)
				send();

			unitOfTime.sleep( intervalOfTime);
		}
	}

	/**
     * Override this one method to provide custom protocol handling
     * (ie: logging, syslog, jms, multicast, etc)
     */
	protected abstract void send(E element);
}
